Amphibious snow vehicle



United. States Patent I Maurice E.- Hebert, 5

-[72] Inventor p .1 Ste-'Foy. Quebec, cm -[2l] -Appl.No. 763525 y [22]Filed Sept. 27, 1968 [45] .'.Pat'ented Oct-20,1970 x I [73] Assignee: Bymesne assignments, to Nanuk Inc.,

Quehee,Canadmncorporation I, I

[54] AMPHIBIOUS SNOW, VEHICLE v 17Claims, IZDra'yving'Figs; v

521 u.s.-c1 115/1 B6Ql'3/00 50 Field orsemh 115/1 I [56] ReferencesCitedI Q f UNITED STATES PATENTS 1 1474;75110/1969 Hebert.....'. v 115/1Pripzqry Eiaminen-Andrew l-L Farrell.

' A ttOrney- C ushmem Darby and Cu'shman ABSTRACT: An amphibious snowvehicle having a buoyant body; supported on an endless track assemblyfor propelling the vehicle on land and impeller wheels associated withthe I endless track drive mechanism for propelling the vehicle ona bodyof water.

Patented 06. 20, 19%

Sheet L of 6 array v: 1

Ptente Oct. 20, 3970 3,534,701

Sheet 6 01'6 7" TOR/K 575 1 mutations SNOW VEHllCLE The presentinvention relates to a motor vehicle and more specifically to a smallamphibious snowmobile.

The majority of prior art vehicles of the miniature type,

such as the two passenger snowmobiles, are propelled by a sin- 7 gleendless track and steered .by skis provided at the front of the vehicle.A disadvantage of this type of vehicle is that it is has to he suddenlyexecuted, this type of vehicle will have a tendency to turn over becauseof its high centre of gravity. When this type of vehicle is occupied bya few passengers the majority of the passcngerweight is to the rearportion of the vehicle, where the seat is located, and the skis will nothave much control on the snow for the reason that .the weight is mainlyover the endless track. A further disadvantage is that these vehiclesare designed for use during the winter season and are restricted fortravel over snow although some adaptations have been provided for theuse of the vehicle over water but when adapted thus, the vehicle isrestricted'for use on stantially free of obstacles such as dead logs,rocks, mud, etc.

Of theclass of amphibious vehicles supported on two tracks,

I the majority of these are large vehicles used for transporting heavyequipment and a large number of people. Because of their large size andof their heavy load these vehicles cannot operate in a heavily bushedterrain and deep soft snow.

It is an object of the present invention to provide a snowmobile whichwill substantially overcome the above-mentioned disadvantages and whichwill operate on land and on water.

According to one broad aspect, the present invention relates to avehicle comprising a buoyant body and an endless track on the undersideof said body supported between a traction train and a rear idle trainassembly to propel said vehicle on land, said traction train assemblyhaving a track engaging drive sprocket wheel rigidly secured to a drivenaxle, the improvement comprising said endless track coacting with one ormore centrifugal pumping wheels secured to said driven axle,

. a portion of said pumping wheels supportingly engaging the endlesstrack for generating a propelling thrust to said vehicle when operatedon water.

The invention is illustrated, by way of example, in the ac' and 2 thereis shown an amphibious snow vehicle generally indicated at 10. Thevehicle consists of a body 11 secured to a frame 12, the body and framepreferably but not exclusively constructed'of glass fibre material. Thecross section of the frame I2 is illustrated by the heavy dotted linesin FIG. 2. The

frame 12 defines two longitudinal cavities 13 of substantiallyrectangular cross section and which extend parallel to the longitudinalaxis of the body of the vehicle and on both sides thereof. A trackassembly 22 is supported in each cavity and protrudes therefrom tosupport the vehicle off the ground.

.slide on the surfaceof the snow. Also, if a sudden sharp turn FIG. 2 isa front view of the snow vehicle as shown in FIG. 1;

in section, of the rear train asflotation casing and supportingassembly;

FIG. 9 is a front view partly in section, of 'the traction trainassembly;

FIG. 10 is a fragmented side view of an impeller wheel;

FIG. 11 is a front view, partly fragmented,'of a portion of a tractiontrain assembly; and

FIG. 12 is a side view, partly in section, of a portion of the front ofthe vehicle showing the impeller wheel.

Between the cavities 13, the frame 12 defines a central portion 14 ofsubstantially rectangular cross section and which protrudes below thecavities at the front of the vehicle and tapers off to the rear of thevehicle to a point which is in the same plane as the opening of thecavities (see surface 3I, FIG.

l). The forward part of the central portion 14 is curved upwardly suchthat the surface 31 of the central portion resembles the configurationof a boat hull; The interior of the central portion 14 contains a gastank and a storage compartment 15 located under a passenger's seat 16.On each side of the body ll there is formed integral therewith anelongated embossed section 17, extending longitudinally to the body 11and defining a bulbous portion 32 in the upper part thereof to furtheradd to the buoyancy and stability of the vehicle when operating onwater.

In the front portion of the vehicle there is provided an engine 23 fordriving the endless tracks 25. The engine is'coupled to the tractiontrain 26 via a differential assembly, generally indicated at 28, whichforms part of the steering mechanism and which is described in detail inapplicants- I copending Canadian application Ser. No. 006,329, filedNov. 29, 1967. In the arrangement shown in FIG. I, the differentialassembly 28 is coupled to a second differential assembly 18 comprising apair of variable diameter pulleys (not shown) secured to an axle. Thedrive of the second differential assuitable reduction ratio may beprovided between bothchain sprocket wheels 19 and 67.

As shown in FIG. I a track assembly generally indicated at v 22 isprovided in each cavity 13. The front of each cavity 13 is curved, asindicated by numeral 7, such that any water which may be ejected in thefront of the cavity,'due to the counterclockwise rotation of the endlesstrack when the vehicle is in movement on a body of water, will be throwndownwardly and develop a slight upward thrust. To decrease anyresistance with the flow of water through the cavities 13, the rearportion 6 of the cavities taper downwardly and angularly rearwardlybehind the rear train assembly. For operation onwater, the vehicle ispropelled by impeller wheels 150, which will be described later indetail. The impeller wheels 150 are secured to the drive shaft of thetraction train 26 and provide a centrifugal pumping action whichdevelops a sufficient propelling.

thrust to displace the vehicle on water. A

Although FIG. 9 shows two impeller wheels, only one of these may beprovided on one side of the sprocket wheel, and the other side of thesprocket would contain a track supporting wheel as described in myabove-mentioned copending application. Referring to FIG. 3 there isshown a water pumping syste for removing any water that may enter thevehicle. Herein shown a syphon tube 116 is disposed in a portion of theexhaust pipe'IlS and protrudes therefrom, so that its end 117 lies closeto the floor of the central portion 14 to pump out any water that mayaccumulate therein. As the burned gases from the engine are forcedthrough the exhaust pipe in the direction of arrow 119, a vacuum iscreated at theend 118 of the syphon tube 116 thus causing a suction inthe tube and drawing any water, that may be present adjacent the end117, through the tube 116 and into the exhaust system (not shown). Toprevent any water from entering into the exhaust system via the exhaustport, when the engine is not operating, a check valve (not shown) islocated in the exhaust port.

Referring to FIGS. 4 and 5 there is shown a rear train assembly 30.Herein shown a rear axle 37 is disposed transversely to the longitudinalaxis of its associated cavity 13 and supported intermediate a pair ofarms 170, each arm 170 being slideably connected in its upper portion tothe frame 12 by means of a bolt 48 cooperating with slot 171 disposedhorizontally in said upper portion of the arm 170. To adjust the tensionin the endless track 25, each pair of arms 170 is selectively displacedalong the horizontal axis of the cavity, this limited distance beingdetermined by the length of the slot 171. To displace each pair of arms170 simultaneously and to maintain them in alignment, both said arms 170are connected together by a connecting bracket 172 of generally U-shapedconfiguration, the connecting bracket 172 comprises two side arms 173fixedly secured, in the forward portion thereof to a respective arm 170of a pair of said arms 170, and interconnected in their rear portion bya transverse piece 174 having an extension 175 at the end thereofprojecting downwardly and normal to the longitudinal axis of the sidearms 173. To selectively adjust the arms 170, an adjusting bolt 176 isthreadably connected to a fixed bracket 177 and is secured at one of itsends to the extension 175 so that by threading or unthreading the bolt176 in the fixed bracket 177, the arm 170 will be displaced horizontallywithin its limited range determined by the length of slot 171.

Referring to FIGS. 6, 7 and 8, there is shown the truck assembly 27. Thetruck assembly consists of one or more hollow flotation casings 120 ofsubstantially rectangular configuration, with the exception of the frontcasing 120 (not shown) in each cavity which is preferably streamlined inits front portion to reduce the resistance with the flow of water underthe vehicle. The flotation casings herein shown are molded from rigidthermoplastic material. On opposite side surfaces 130, of each casing120, there is provided a pair of circular recesses 131 of selecteddiameter for receiving a respective supporting rubber mount 132. Thefree end portion of the supporting rubber mount 132 engaging in therecess 131 is provided with a plurality of circumferential ridges 133,each of the ridges 133 sloping downwardly away from the secured end ofthe mount 132 so that when the free end portion is inserted in therecess 131 a vacuum is created in the recess which prevents the free endfrom disengaging therewith. The fixed end portion of each mount 132 isprovided with a lug 134 embedded therein and adapted to receive a bolt135 passing through the frame 12 for securing the mount 132 thereto.

With this arrangement it can be seen that when the vehicle is travellingover rough terrain, the casings 120 will absorb some of the shocks forthe reason that the rubber mounts 132 will be flexed when the casing issubjected to an upward push when the endless track 25 passes overobstacles.

As can be seen from FIG. 8, the lower edge of the frame 12, defining theouter side of each cavity is reinforced throughout with an aluminumstrip 136 shaped to the contour of the lower edge and secured thereto bythe bolts 135.

In the lower surface 121 of each flotation casing 120, there is providedfour wheel receiving cavities 122, one substantially in each corner ofthe flotation casing 120, to receive a portion of a supporting wheel 123therein and to permit free rotation thereof. Each pair of adjacentwheels 123 is secured on a respective axle 124 which is held in thelower surface 121 of the casing 120, transversely to the longitudinalaxis of the cavity 13. The axle 124 is held in an elongated recess 125which is disposed normal to the longitudinal axis of the casing 120 andin its lower surface 121, and aligned with the centre of the diameter ofadjacent wheel receiving cavities 122 at a respective end of the casing120. The elongated recess 125 is of substantially U-shaped crosssection, the sides of the U-configuration tapering slightly inwardlytowards each other, and curvilinearly outwardly to the lower surface 121of the casing 120, to define a boss 126 in the sides of the recess 125to retain the axle 124 therein. The wheels 123 are mounted on arespective oiled bearing 127 and held in a fixed position, at theirrespective end of the axle 124, by means of a rubber bushing 128 andwasher 129 located on each side of the wheel 123 and bearing 127 andabutting against the lower portion of the sides of the cavity 122. Theportion of the elongated recess receiving the rubber bushings 128, isslightly larger than the portion receiving the axle 124. To secure thewheels 124 in position, the axle assembly is merely snapped in positionin the elongate recess 125.

Centrally located in the upper surface 137 of the flotation casing 121,is a wheel receiving cavity 138 for retaining a track supporting idlersprocket wheel 139. The cavity 138 is of substantially U-shaped crosssection and defines a recess 140 in each side thereof and disposedadjacent each other to sup port an axle I41 horizontally and parallel toaxles 124. The

recesses 140 are substantially U-shaped and define a boss 142 in theupper end of its respective side faces to retain the axle 141 fittedwith a rubber bushing 143 about each end. The track supporting idlersprocket wheel 139 is mounted on an oilite bearing 144 held in position,in the cavity 138, by a washer 145 disposed on each side thereof andabutting against the walls of the U-shaped cavity 138. To position thetrack supporting idler sprocket wheel assembly, the ends of the axle141, fitted with a respective bushing 143, are snapped in position intheir respective recess 140. Although, herein described a tracksupporting idler wheel assembly is provided in the upper surface 137 ofthe flotation casing 121, this assembly may not be necessary and thetracks may be supported, in its upper travel, on the flat upper surface137 of the casing 121.

As shown in FIG. 6 a guide sprocket wheel 41 may be provided in thelower surface of the flotation casing 120 and centrally positionedtherein in a cavity and secured to the casing in a similar manner asthat described hereinabove for wheels 123. The sprocket wheel 41 extendsfrom the lower surface 121 of the casing 120 and engages with the centreof the endless track 25 to prevent lateral displacement of the track 25when the vehicle executes a turn or is driven over rough terrain. Theidle sprocket wheel 41 may be provided only in the middle truck 27 ofthe complete endless track assembly.

Referring now to FIG. 9 there is shown the traction train assembly 26for driving the endless tracks 25 (see FIG. 1). Although FIG. 9 onlyshows one traction train assembly, identical assemblies are provided onboth sides of the vehicle. The traction train assembly, generallyindicated at 26, comprises a shaft 61 supported in the front portion ofthe cavity 13 and transversely to the longitudinal axis of the vehicle,and extending a limited distance inside the central portion 14 of theframe 12. The shaft 61 is supported by bearings 62 which provideslimited axial displacement of the shaft 61. The bearings 62 also preventleakage between the cavity 13 and the central portion 14 when thevehicle is used on water. To drive the endless track a sprocket wheel 63is rigidly secured to the shaft 61 and located at the centre of thewidth of the cavity 13. The endless track is supported laterally byimpeller wheels 150, the main purpose of which will be described later,positioned on each side of the sprocket wheel 63 and spaced equidistantfrom the sprocket wheel 63 by an inner and outer spacer member 65 and 66respectively, on the shaft 61.

The portion of the shaft 61 which extends in the central portion 14 ofthe frame 12, is provided with a chain sprocket wheel 67.

As shown in FIG. 10 and 11, each impeller wheel comprises a circular hubportion 151 having a central bore 152 therein and a plurality ofarcuately extending vanes 153 equidistantly spaced about the cylindricalsurface 162 of the hub and disposed between a pair of circular sideplates 154 centrally secured on a respective side of the hub portion 151and lying substantially parallel to each other, although in FIG. 9 theseare shown inclined inwardly and for a specific reason as will bedescribed later. Each vane 153 extends transversely across theperipheral surface 162 of the hub portion and outwardly to the outerperiphery of the circular side plates 154.

The side'plates 154 are each provided with an aperture 155 near itscentre, the aperture 155 being slightly larger in diameter than the hubportion 151. The edges of the vanes 153 extend from the ends of thecylindrical surface 162 of the hub portion and converge curvilinearlyoutwardly to the periphery of a respective aperture 155 thus defining aninlet port 156, on each side of the impeller wheel 150, to the passages161 defined between adjacent ones of said vanes 153.

As can be seen from reference to FIG. 11, the impeller 150 is securedover a sleeve 157 fitted about the shaft 61. by means of a tension pin158 disposed in a bore provided across the hub portion 151, the-sleeve157 and the shaft 61.

The thrust provided by the impeller 150 is derived from the centrifugalpumping action caused by the rotation of the impeller in acounterclockwise direction, as indicated by arrow 159 in FIG. 12. It canbe seen from FIG. 12 that when the vehicle is operating on a body ofwater, the impeller wheel 150 is substantially completely submerged inwater in insure that water is everpresent at the inlet port 156. Whenthe endless tracks are in movement, to cause forward displacement of thevehicle, the impellers 150 rotate and the water present at the inletports 156 is drawn into the impeller passages 161, by the centrifugalaction created by the rotating vanes 153, and is thrown outwardlytowards the outer end of the passages 161. Because the endless trackpasses about a portion of the im peller wheels 150 (see FIG. 12) thewater thrown outwardly in the passages 161 cannot escape because theendless track covers the opening at the outer end of these passages andthe result is that this water is discharged rearwardly of the impellerwheels at a velocity dependent upon the speed of rotation of theimpeller wheels. This rearward discharge imparts a forward thrust to thevehicle which is sufficient to adequately displace the vehicle on water.

Although the side plates 154 are shown lying substantially parallel toeach other, these may be inclined slightly inwardly, as shown in FIG.13, to reduce the surface area of the opening at the outer end of thepassages thereby increasing the pressure of the water being ejectedtherethrough by the centrifugal action created by the rotating impellerwheel.

In operation, the vehicle is displaced on land by the endless tracks 25and steered by the steering assembly 241 associated with thedifferential assembly 28. For a complete description of the steeringmechanism, reference is made to applicants aforementioned copendingapplication.

The propelling of the snowmobile on a body of water is effected by theimpeller wheels and the steering of the vehicle is being effected in thesame manner as on land, that is, by the steering mechanism. Bydisplacing the steering arms to the right or to the left the speed ofthe drive shafts of the traction train in the respective cavities arevaried inversely one with respect to the other and the thrust generatedby the impeller wheels associated with these drive shafts will increaseon one side of the vehicle and decrease on the opposite side therebycausing the vehicle to execute a turn. As mentioned hereinabove, thethrust developed by the centrifugal pumping action of the impellerwheels is sufficient to adequately displace the vehicle. However, if itis desirable to obtain further propulsion and consequently highervehicle speeds when operating on water, the impeller wheels may berotated at a higher velocity that the velocity as when used on land. Inorder to obtain this increase in the drive speed an arrangement (notshown) may be provided whereby the drive ratio can be increased simplyoperating a control which would cause engagement of another sprocketratio.

Iclaim:

1. In a vehicle having a buoyant body and an endless track on theunderside of said body supported between a traction train and a rearidle train assembly to propel said vehicle on land, said traction trainassembly having a track engaging drive sprocket wheel rigidly secured toa driven axle the improvement comprising said endless track coactingwith one or more centrifugal pumping wheels secured to said driven axle,a portion of said pumping wheels supportingly engaging the 2. A vehicleas claimed in claim 1 wherein said centrifugal pumping wheels areimpeller wheels.

3. A vehicle as claimed in claim 2 wherein said impeller wheels orwheels comprise a bored hub portion having a plurality of arcuate vanesextending therefrom and two circular side plates centrally positionedwith respect of said hub portion and secured on a respective side ofsaid hub portion, and an aperture near the centre of each said sideplates to provide an inlet port to the passages betweensaid vanes.

43. A vehicle as claimed in claim 3 wherein said vanes are disposedtransversely across the outer surface of said hub portion.

5. A vehicle as claimed in claim 3 wherein the said vanes extend fromthe outer surface of said hub portion and converge curvilinearlyoutwardly to the outer periphery of said plates.

6. A vehicle as claimed in claim 3 wherein two impeller wheels aresecured to said driven axle and positioned on a respective side of saidtrack engaging drive sprocket wheel which is secured at the centre ofsaid driven axle.

7. A vehicle as claimed in claim 3 wherein said impeller wheel issecured to said driven axle by a tension pin positioned in a borediametrically disposed across said hub portion and. said driven axle.

8. A vehicle as claimed in claim 3 wherein said side plates are parallelto each other.

9. In a vehicle having a buoyant body, a pair of elongated cavities inthe underside of said body disposed parallel to the fore/aft axis ofsaid vehicle, an endless track supported in each said cavities between atraction train and a rear idle train assembly to propel said vehicle onland, said traction train having a track engaging d riy e sprocket wheelrigidly secured to a driven axle, the improvement comprising each saidendless tracks coating with one or more centrifugal pumping wheelssecured to said driven axle, a portion of said pumping wheelssupportingly engaging the endless track for generating a propellingthrust to said vehicle when operated on water.

10. A vehicle as claimed in claim 9 wherein said centrifugal pumpingwheels are impeller wheels.

11. A vehicle as claimed in claim 10 wherein said impeller wheel orwheels comprise a bored hub portion having a plurality of arcuate vanesextending therefrom and two circular side plates centrally positionedwith respect to said hub portion and secured on a respective side ofsaid hub portion, and an aperture near the centre of each said sideplates to provide an inlet port to the passages between said vanes.

12. A vehicle as claimed in claim 11 wherein said vanes are disposedtransversely across the outer surface of said hub portion.

' 13. A vehicle as claimed in claim 11 wherein the said vanes extendfrom the outer surface of said hub portion and converge curvilinearlyoutwardly to the outer periphery of said side plates.

14. A vehicle as claimed in claim 11 wherein two impeller wheels aresecured to said driven axle and positioned on a respective side of saidtrack engaging drive sprocket wheel which is secured at the centre ofsaid driven axle.

15. A vehicle as claimed in claim 11 wherein said impeller wheel orwheels are secured to said driven axle by a tension pin positioned in abore diametrically disposed across said hub portion and said drivenaxle.

16. A vehicle as claimed in claim 11 wherein said side plates areparallel to each other.

17. A vehicle as claimed in claim 9 wherein said centrifugal pumpingwheels are impeller wheels each having a bored hub portion, a pluralityof arcuate vanes extending from said hub portion and two circular sideplates centrally positioned with respect to said hub and secured on arespective side thereof, an aperture near the centre of each said sideplates to provide an inlet port to passages between said vanes so thatwhen said impeller wheel is rotated in water, the water will be drawninto tion of water in this portion of said wheel to thereby provideejection of water only in a general rearward direction of said vehicle.

